An object detection apparatus for detecting an object around a moving object by transmitting a probe wave and receiving reflections of the probe wave from the object via the plurality of ranging sensors. In the apparatus, an interaction determiner is configured to, if an object position calculated by a position calculator is within a range of a moving-object's course, determine whether or not the detected object is likely to interact with the moving object based on a lateral position of the detected object and a degree of confidence of the object position calculated by the position calculator. The lateral position of the detected object is the object position calculated by the position calculator in a direction perpendicular to a moving direction of the moving object.